This invention relates to printing arrangements for devices having memory registors which repeat read and write functions periodically. Generally, there are two types of memory devices. The first is of the condenser memory type, wherein data is not retained unless the read and write functions are repeated periodically. The second type of memory device is of the magnetic core type, wherein once data is written, it can be retained until a rewrite signal is applied. The period of a memory register is the period of the periodic repeat of the read and write functions within the memory register, which period is generally controlled by functions within the device other than the display function, although synchronization with the display function is sometimes provided. For example, in an electronic computer, the "period" is the period of bits, figures or memory cycles which is read and written for the purposes of calculating. Generally, the clock of an electronic computer operates at from several to several hundred times as fast as a printer. For this reason, although a memory register for the purposes of calculation and/or display is generally provided within a computer, printing devices are generally not driven directly by the output signal of the memory register, since the conventional printing devices cannot respond to the reading and writing speed of the conventional memory register. Generally, conventional printers are driven indirectly by applying the contents of the memory register of the computer to another temporary memory register which can memorize the information until printing is completed. The contents of the temporary memory register are read out continuously until printing or selection of characters is completed. Such a driving method for a printer can be characterized as being indirect, inasmuch as the signals indentifying the characters to be printed are not directly applied by the memory register of the computer, but rather are applied through a second temporary memory register.
On the other hand, where electronic displays are utilized in conjunction with computers or similar devices, the electronic display is generally driven directly by the output of the main memory register. Such display devices, such as fluorescent display devices, may be driven by applying the contents of the main memory register for calculation directly to the display device at the calculating cycle of reading and writing utilizing the scanning method for driving the fluorescent display device, since the display device can operate at a speed sufficiently fast to respond to the clock or "period" of the computer. By providing a print device driven directly by the main memory register, as in the case of fluorescent display devices, the foregoing deficiencies in known printing devices are avoided.